Light emitting diodes or “LEDs” are solid state devices that convert electrical energy into light. LEDs can be utilized in light emitter devices or components for providing different colors and patterns of light useful in various lighting, display, and optoelectronic applications. One such application is the use of LEDs in video screens. LED video displays typically comprise arrays of red, green, and blue LEDs mounted on a single electronic device attached to a printed circuit board (PCB) that controls the output of each electronic device.
Conventional LED arrays often have a transparent encapsulant covering the individual LEDs to protect the devices and maximize the efficiency of the devices. When used in applications such as video screens, it may be additionally desirable to reduce and/or enhance the amount of reflected light. Controlling the amount of reflected light can provide benefits such as increased contrast, image sharpness, and consistent color quality across viewing angles.
Additionally, LED devices, such as video screens, continue to increase in size and density, while the size of the individual components making up these devices has been decreasing. Accordingly, the time and effort required to construct these devices has also been increasing. As such, it is desirable to improve the speed of LED component placement in these devices while maintaining desired light output features and controlling costs.
In particular, a known problem with LED arrays is color quality in the far-field. The far field can be generally defined as the intensity pattern observed from a distance much larger than the source. Individual LEDs in a grouped array may have different light output properties, which become more apparent when seen from a wide viewing angle. For example, some colors of LEDs can have wider light output cones and thus dominate the overall color tone at the extents of the viewing region, resulting in undesirable color quality. Hence, there is a continuing need for improvements to encapsulated LED arrays.